GM-CSF-Induced Metal Sequestration and Histoplasma

致病真菌，组织胞浆菌，是美国中西部和东南部的地方病， 是呼吸道真菌感染最常见的原因。有机体在 单核细胞（Mo）和巨噬细胞（M β）的细胞内环境，并具有 建立一个潜在的国家。采用多学科方法，包括金属组学，免疫学， 细胞生物学和生物信息学，我们的研究已经确定了新的功能，粒细胞 巨噬细胞集落刺激因子（GM-CSF）和白细胞介素（IL）-4有助于解释其 钼/钼比值对真菌生长的影响不同。GM-CSF剥夺机体的锌 在细胞内同时促进活性氧物质的产生。最终的结果 是杀死酵母细胞 另一方面，IL-4通过强化细胞内的细胞因子， 组织胞浆菌可利用的锌量。GM-CSF和IL-4活性的关键是 金属硫蛋白（MT），其储存和提供锌，以及锌转运蛋白。它们是一个中心节点 介导细胞因子活化和效应子功能之间的联系。对于GM-CSF，MT 1和2是 而对于IL-4，它是MT3。在本提案中，我们将以我们在2010年期间开展的工作为基础， 最后一个融资周期并深入探索MT-锌轴如何调节GM-CSF的活性 和IL-4对人和小鼠Mo/M β的影响。我们已经收集了令人兴奋的数据，糖酵解控制着 在感染的GM-CSF刺激的Mo/M β中MTs 1和MTs 2的表达。另一方面，MT3缓和了 在这些细胞中IL-4激活的糖酵解反应。目标1将破译糖酵解如何塑造 MT 1和2表达和细胞内Zn 2+分布以支持Mo/M β效应器功能。 目的2 将定义GM-CSF激活的Mo/M受体的细胞内改变，其拒绝真菌进入 锌和MTs 1和2对这些吞噬细胞发挥的宿主防御的体内作用。目标3将 阐明糖酵解和MT3在形成IL-4生理学中的交叉点， 组织胞浆菌感染的Mo/M。这些研究将为细胞因子调控提供新的见解， 组织胞浆菌感染Mo/M.

The pathogenic fungus, Histoplasma capsulatum, is endemic to the Midwestern and Southeastern US and is the most frequent cause of respiratory fungal infection. The organism thrives within the intracellular environ- ment of monocytes (Mo) and macrophages (Mɸ) and has the capacity to establish a latent state. Employing a multidisciplinary approach including metallomics, immunology, cell biology and bioinformatics, our studies have identified novel functions of granulocyte macrophage colony-stimulating factor (GM-CSF) and interleukin (IL)-4 that help to explain their disparate effects on the growth of the fungus with Mo/Mɸ. GM-CSF deprives the organism of zinc intracellularly while concurrently boosting production of reactive oxygen species. The end result is killing of yeast cells. On the other hand, IL-4 promotes intracellular survival by fortifying the amount of zinc available to Histoplasma. Crucial to the activities of GM-CSF and IL-4 are metallothioneins (MTs), which store and donate zinc, and zinc transporters. They are a central node mediating the link between cytokine activation and effector function. For GM-CSF, MTs1 & 2 are essential whereas for IL-4, it is MT3. In this proposal, we will build on our work conducted during the last funding cycle and explore in depth how the MT- zinc axis regulates the activity of GM-CSF and IL-4 on human and mouse Mo/Mɸ. We have collected exciting data that glycolysis governs the expression of MTs1&2 in infected GM-CSF-stimulated Mo/Mɸ. On the other hand, MT3 tempers the glycolytic response in IL-4 activated in these cells. Aim 1 will decipher how glycolysis molds MT1&2 expression and intracellular Zn2+ distribution to bolster Mo/Mɸ effector function. Aim 2 will define the intracellular alterations in GM-CSF-activated Mo/Mɸ that deny the fungus access to zinc and the in vivo effect of MTs1&2 on host defenses exerted by these phagocytes. Aim 3 will elucidate the intersection of glycolysis and MT3 in shaping the physiology of IL-4 on Histoplasma-infected Mo/Mɸ. These studies will provide new insights into cytokine regulation of metabolism and metallobiology in Histoplasma-infected Mo/Mɸ.